In recent years, there have been concerns such as global warming and aerial pollution caused by carbon dioxide (CO2), nitrogen oxide (NOX), and suspended particulate matter (PM) contained in an exhaust gas of an vehicle. For this reason, instead of an existing gasoline internal-combustion engine vehicle, a fuel cell vehicle (FCV) which is driven by using electric energy based on an oxidization reaction between hydrogen and oxygen in a fuel cell mounted on the vehicle has been gaining attention.
The fuel cell vehicle does not discharge any toxic matter in addition to the above-described carbon dioxide and the like. Further, the fuel cell vehicle has energy efficiency better than that of the gasoline internal-combustion engine vehicle. Likewise, the fuel cell vehicle has various advantages that may not be obtained from the gasoline internal-combustion engine vehicle.
Incidentally, the fuel cell vehicle may be largely classified into a type in which hydrogen is charged from a hydrogen station to the vehicle and a type in which a fuel other than hydrogen is charged to the vehicle and hydrogen is produced in a vehicle installed reforming unit. However, the former type has more advantages from the effect of a reduction of carbon dioxide (CO2). Accordingly, there is a need to more actively study and develop the fuel cell vehicle and the hydrogen station that charges hydrogen to the fuel cell vehicle.
In a case of the fuel cell vehicle of the type in which hydrogen (hydrogen gas) is charged from the hydrogen station to the vehicle, compressed hydrogen is charged to a hydrogen tank mounted on the vehicle.
Incidentally, in a case where a gas is expanded while a difference in pressure thereof is maintained when a high-pressure gas of a supply source is transferred (that is, expanded) to a low-pressure state of a supply target, a change in temperature occurs in the gas due to the Joule-Thomson effect.
A change in temperature caused by the Joule-Thomson effect depends on the initial temperature of the gas. When the initial temperature is equal to or lower than the inversion temperature, the temperature of the gas decreases. Then, when the initial temperature is higher than the inversion temperature, the temperature of the gas increases. Here, the inversion temperature of the hydrogen is about 215 K (−58.15° C.). Since this inversion temperature is fairly lower than those of the other gases, when the hydrogen is generally charged to the hydrogen tank of the fuel cell vehicle or the like, an abrupt increase in temperature occurs in the charged hydrogen.
Accordingly, in the hydrogen station, there is a need for equipment or the like to suppress an abrupt increase in the temperature of the hydrogen when the hydrogen is charged to the hydrogen tank. Thus, various proposals have been suggested. For example, Patent Document 1 discloses a method of rapidly charging hydrogen to a hydrogen tank (and a hydrogen station that realizes the rapid hydrogen charging method), where the method includes: connecting a hydrogen supply source to a hydrogen tank and increasing a hydrogen charging speed in response to a pressure inside the hydrogen tank by a charging speed changing unit provided in a passage connecting the hydrogen supply source to the hydrogen tank.
Further, the hydrogen station includes a compressor (a high-pressure compressor) which compresses hydrogen in a high-pressure state so as to supply the compressed hydrogen to a fuel cell vehicle or the like. The compressor is activated when the hydrogen is supplied (charged) to the fuel cell vehicle or the like in the hydrogen station.
In this way, since the hydrogen is supplied after the unit such as the compressor is activated (started up) in the hydrogen station, it takes some time until the supply of the hydrogen is actually started after an order to start up the supply of the hydrogen is received.
Therefore, a case may be supposed in which all units of the hydrogen station including the compressor are activated (started up) before the order to start up the supply of the hydrogen to the fuel cell vehicle or the like is received, but in this case, power consumption increases.